GB/T 5304-2001 Standard Test Method for Thin-Film Oven Test of Petroleum Asphalt

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Card type: Test method

1. Method number / full name / English name / replacement relationship

• Standard number: GB/T 5304—2001
• Chinese full name: Standard Test Method for Thin-Film Oven Test of Petroleum Asphalt
• English name: Asphalt thin-tilm oven test method (as in the source text, suspected to be thin-film, requires confirmation against the source standard (source-text extraction))
• Replacement relationship: replaces GB/T 5304—1985
• Adoption relationship: equivalent adoption of ASTM D1754—1997 "Test Method for Effect of Heat and Air on Asphalt Quality"
• Approval/implementation: approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China 2001-05-11, implemented on 2001-12-01
• Main differences from GB/T 5304—1985 (original foreword): specifies the oven volume dimension range and adds "the maximum dimension of each side of the oven is 535 mm"; the thermometer hanging position is changed from "the bottom of the mercury bulb should be 6.4 mm above the turntable" to "40 mm"; the turntable diameter is changed from "not less than 250 mm" to "250～450 mm"; the turntable installation position is changed from "as close as possible to the center of the oven" to "should be 150 mm above the bottom of the oven"; the report adds "mass decrease is reported as a negative value, mass increase is reported as a positive value"; adds precision requirements for 15°C ductility, 60°C viscosity, 135°C viscosity and 60°C viscosity ratio before and after the test; adds the requirement "within 72 h, complete the determination of the properties of the sample after heating".
• Main differences from ASTM D1754—1997 (original foreword): the thickness of the metal dish of the sample container ASTM is specified as approximately 0.64 mm, this standard specifies 0.6～1.0 mm; deletes the oven recommended in ASTM Annex X1, adds Annex A specifications for the thermometer used in the instrument; does not adopt the requirements of "standard deviation" and "coefficient of variation" in the precision requirements of test results of ASTM.
• Annex: Annex A is a standard annex.

2. Scope of application and non-applicability

• This standard is applicable to the determination of the effect of heat and air on a thin film of petroleum asphalt. This effect is determined by measuring changes in certain properties of the petroleum asphalt before and after the test.
• This standard does not specify safety-related issues; if necessary, the user should establish appropriate personal safety protection measures before use.
• Not applicable: no other explicit non-applicable scope is provided in the available source.

3. Method principle

• A thin film of petroleum asphalt is heated in an oven at 163°C for 5 h; by measuring the physical properties of the sample before and after the test, the effect of heat and air on the properties of the petroleum asphalt and the mass change of the sample before and after the test are determined (3.1).
• This standard specifies the precision for viscosity, viscosity ratio, penetration ratio, mass change and ductility (3.2).
• Significance and application: it can be used to predict changes in the properties of petroleum asphalt during normal hot mixing (approximately 150°C), usually expressed by viscosity, penetration and ductility. The properties of the petroleum asphalt after the test are close to the quality of the petroleum asphalt laid into the road. If the hot mixing temperature differs significantly from 150°C, the effect on the quality of the petroleum asphalt will be greater or less than the measured data (Chapter 4).

4. Reagents and materials (purity / preparation)

• Not provided in the available source.

5. Instruments and equipment

• 5.1 Oven: electrically heated air natural convection oven. The working temperature can reach 180°C. The turntable shaft should be aligned with the center of the oven and should rotate well after installation.
  • 5.1.1 Structure: the oven is rectangular, the minimum dimension of each side inside the oven is 330 mm, and the maximum dimension is 535 mm (excluding the space occupied by the heating element). A tightly fitting hinged door should be installed on the front of the oven; the size of the door is approximately the same as the internal height and width of the oven. A window of at least 100 mm×100 mm may be installed on the door, fitted with two layers of glass with an air gap in between. The reading of the thermometer inside the oven can be measured through the window without opening the oven door; it is also permissible to provide an additional glass door inside the oven door. The oven uses natural air convection ventilation. To make the air exchange in the oven uniform, an air inlet and an air outlet are provided at the bottom and top respectively; the total area of the air inlet is at least 1.3 cm², and the total area of the top gas outlet is 1.3～12.9 cm² (the unit in the source text is suspected to be cm², requires confirmation against the source standard (source-text extraction)).
  • 5.1.2 Turntable: the oven should have a metal circular disk with a diameter of 250～450 mm. The structure of this disk should be a flat plate on which the sample containers are placed. When the sample containers are placed on it, air circulation through the turntable should not be blocked. The turntable is installed on a suspended vertical shaft and positioned at the exact center of the horizontal dimensions inside the oven. The turntable is rotated by a dedicated mechanical device at a speed of (5.5±1.0)r/min (the unit in the source text is suspected to be r/min, requires confirmation against the source standard (source-text extraction)); the turntable should be positioned vertically, and the optimal vertical position should be 150 mm above the bottom (excluding the space occupied by the heating element).
• 5.2 Thermometer: complies with the provisions of Annex A. The thermometer is hung on the bracket of the vertical shaft of the turntable; the distance from the hanging point to the center and the edge of the turntable should be equal; the bottom of the mercury bulb of the thermometer should be 40 mm above the turntable.
• 5.3 Sample container: flat-bottomed cylindrical dish. Inner diameter 140 mm, depth 9.5 mm; a sample of 50 g forms a film approximately 3.2 mm thick in this sample container. The sample container may be made of stainless steel or aluminum, with a metal thickness of 0.6～1.0 mm, and should not deform during use.
• 5.4 Analytical balance: used for accurate weighing, accurate to 0.001 g.
• Annex A Specifications of the thermometer used in the instrument:
  • A1 This specification complies with the specification of ASTM E1 13C (as in the source text, requires confirmation against the source standard (source-text extraction)).
  • A2 This thermometer should meet the following requirements:
    • Temperature range: 155～170°C
    • Immersion depth: total immersion
    • Minimum division: 0.5°C
    • Each longer scale: 1°C
    • Numbered: 155,160,165,170
    • Scale error: ≤0.5°C
    • Expansion chamber allowed to be heated to: 200°C
    • Overall length: 150～160 mm
    • Stem diameter: 5.5～7.0 mm
    • Mercury bulb length: 10～15 mm
    • Mercury bulb diameter: ≥5.0 mm (must not be thicker than the stem)
    • Distance from the bottom of the bulb to the 155°C scale: 50～60 mm
    • Length of the graduated portion: 40～60 mm
    • From the bottom of the bulb to the top of the contraction bulb: 30 mm

6. Recommended operating conditions

• Test temperature: (163±1)°C.
• Heating time: maintain for 5 h; the starting time of 5 h is from the temperature rising to 162°C, but the time of the sample in the oven should not exceed 5.25 h.
• Turntable rotation speed: (5.5±1.0)r/min (the unit in the source text requires confirmation against the source standard (source-text extraction)).
• Turntable vertical position: optimally 150 mm above the bottom of the oven (excluding the space occupied by the heating element).
• Position of the bottom of the thermometer mercury bulb: 40 mm above the turntable.
• Oven leveling: when the turntable rotates on a horizontal plane, the tilt angle between the turntable and the horizontal plane is not greater than 3°.
• Note: it is not permitted to test different grades of asphalt in the same oven at the same time.

7. Sampling and sample preparation

• 6.1 Place sufficient sample in a suitable container, heat to a fluid state; during heating, avoid local overheating of the sample; the maximum heating temperature must not exceed 150°C; during heating, stir the sample, but avoid generating bubbles in the sample. In sample containers that meet the requirements of 5.3 and have a known mass, weigh (50±0.5)g of sample respectively.
• 6.2 Pour the sample from 6.1 simultaneously into the test molds of the analytical instruments required for determining the properties of the petroleum asphalt before the test, and carry out the determination of viscosity, penetration, etc. of the sample before the test according to the referenced standards.
• 6.3 If the mass change does not need to be determined, proceed according to 7.2. If the mass change needs to be determined, the weighed sample should be cooled to room temperature and then weighed to the nearest 0.001 g.

8. Analytical procedure

• 7.1 Level the oven; when the turntable rotates on a horizontal plane, the tilt angle between the turntable and the horizontal plane is not greater than 3°.
• 7.2 Place the empty sample containers in the predetermined positions on the turntable. When the oven is in equilibrium, adjust the temperature control switch to control the temperature at (163±1)°C.
• 7.3 After preheating and adjusting the oven according to the requirements of 7.2, while removing the empty sample containers, quickly place the sample containers containing the sample onto the turntable. Close the oven door and start rotating the turntable. After the sample is placed in the oven and the temperature inside the oven rises again to the required temperature, maintain at (163±1)°C for 5 h. The starting time of 5 h is from the temperature rising to 162°C, but the time of the sample in the oven should not exceed 5.25 h. After the test is completed, remove the sample from the oven. If the mass change of the sample does not need to be determined, proceed according to 7.5. If the mass change of the sample needs to be determined, cool the sample to room temperature and then weigh to the nearest 0.001 g.
• 7.4 After weighing the sample, place it on the turntable of the 163°C oven, close the oven door, rotate the turntable for 15 min, remove the sample, and immediately proceed to the next step according to 7.5.
• 7.5 Scrape the sample from each sample container with a suitable scraper or putty knife, and pour it into a porcelain dish or metal dish of 240 mL. Stir and mix the sample thoroughly. If necessary, the porcelain dish or metal dish may be placed on a heating plate to keep the sample in a fluid state. Within 72 h, use the test methods specified in the referenced standards to complete the determination of viscosity, penetration and ductility, etc. of the sample after the test.

9. Qualitative and quantitative and calculation formulas

• 8.1 Report the viscosity and penetration of the test sample measured according to 6.2 and 7.5. The viscosity ratio is expressed as the ratio of the viscosity of the petroleum asphalt after the test to the viscosity of the petroleum asphalt before the test. The penetration ratio is expressed as the percentage of the penetration of the petroleum asphalt after the test relative to the penetration of the petroleum asphalt before the test.
• 8.2 Report the ductility or other test results of the test sample measured according to 7.5.
• 8.3 When reporting mass change, the mass change is expressed as the percentage of the mass change in all sample containers relative to the mass of the test sample before the test. Mass decrease is reported as a negative value, and mass increase is reported as a positive value.
• 9.1 The penetration ratio of the test sample P. (%) is calculated according to the following formula:
  • P. = P / P₀ × 100 …… (1)
  • Where: P— penetration of the test sample after the test, 1/10 mm; P₀—penetration of the test sample before the test, 1/10 mm.
  • (The formula symbol source-text extraction in the source text is noisy, requires confirmation against the source standard (source-text extraction))
• 9.2 The mass change of the test sample M. (%) is calculated according to the following formula:
  • M. = (m − m₀) / m₀ × 100 …… (2)
  • Where: m— total mass of the test sample after the test, g; m₀—total mass of the test sample before the test, g.
  • (The formula source-text extraction in the source text is noisy, requires confirmation against the source standard (source-text extraction))
• 9.3 The 60°C viscosity ratio of the test sample V. is calculated according to the following formula:
  • Where: η— viscosity of the test sample 60°C after the test, Pa·s; η₀—viscosity of the test sample 60°C before the test, Pa·s.
  • (The formula body source-text extraction in the source text is missing, requires confirmation against the source standard (source-text extraction))

10. Precision

• 10.1 Repeatability: within the same laboratory and by the same operator, the difference between two results shall not exceed the value in Table 1.
• Table 1 (Repeatability):
  • Penetration ratio, %: allowable difference between two test results 4.0; allowable range (percentage of the average) not provided in the available source.
  • Absolute value of mass change, %: when ≤0.4%, allowable difference 0.04; when >0.4%, allowable difference 0.16; allowable range (percentage of the average) not provided in the available source.
  • 60°C viscosity: allowable difference 20; allowable range (percentage of the average) not provided in the available source.
  • 135°C viscosity: allowable difference 8.0; allowable range (percentage of the average) not provided in the available source.
  • 60°C viscosity ratio: allowable difference 8.0; allowable range (percentage of the average) not provided in the available source.
  • Ductility (15°C), cm: allowable difference 9.3; allowable range (percentage of the average) not provided in the available source.
  • (The correspondence between the values in Table 1 and the items source-text extraction is misaligned, requires confirmation against the source standard (source-text extraction))
• 10.2 Reproducibility: in different laboratories and by different operators, the difference between two test results shall not exceed the value in Table 2.
• Table 2 (Reproducibility):
  • Penetration ratio, %: allowable difference between two test results 8.0; allowable range (percentage of the average) not provided in the available source.
  • Absolute value of mass change, %: when ≤0.4%, allowable difference 0.16; when >0.4%, allowable difference 40.0; allowable range (percentage of the average) not provided in the available source.
  • 60°C viscosity: allowable difference 33.0; allowable range (percentage of the average) not provided in the available source.
  • 135°C viscosity: allowable difference 18.0; allowable range (percentage of the average) not provided in the available source.
  • 60°C viscosity ratio: allowable difference 26.0; allowable range (percentage of the average) not provided in the available source.
  • Ductility (15°C), cm: allowable difference 34; allowable range (percentage of the average) not provided in the available source.
  • (The correspondence between the values in Table 2 and the items source-text extraction is misaligned, requires confirmation against the source standard (source-text extraction))

11. Report

• 8.1 Report the viscosity and penetration of the test sample measured according to 6.2 and 7.5. The viscosity ratio is expressed as the ratio of the viscosity of the petroleum asphalt after the test to the viscosity of the petroleum asphalt before the test. The penetration ratio is expressed as the percentage of the penetration of the petroleum asphalt after the test relative to the penetration of the petroleum asphalt before the test.
• 8.2 Report the ductility or other test results of the test sample measured according to 7.5.
• 8.3 When reporting mass change, the mass change is expressed as the percentage of the mass change in all sample containers relative to the mass of the test sample before the test. Mass decrease is reported as a negative value, and mass increase is reported as a positive value.

12. Normative References

• GB/T 4509 Standard Test Method for Penetration of Bituminous Materials
• GB/T 4508 Standard Test Method for Ductility of Bituminous Materials
• SH/T 0557 Standard Test Method for Viscosity of Petroleum Asphalt (Vacuum Capillary Method)
• SH/T 0654 Standard Test Method for Kinematic Viscosity of Asphalt
• Note: The source text Chapter 2 states that the provisions contained in the following standards, through reference, become part of this standard. Unless otherwise explicitly specified in the standard, the following referenced standards shall all be the currently effective versions.

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick Reference Q&A